From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andrew Morton Subject: Re: [PATCH] VFS mmap wrong behavior when I/O failure occurs Date: Wed, 11 May 2005 01:19:16 -0700 Message-ID: <20050511011916.611486e7.akpm@osdl.org> References: <1115837231.3599.55.camel@CoolQ> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Cc: viro@parcelfarce.linux.theplanet.co.uk, linux-fsdevel@vger.kernel.org, iscas-linaccident@intellilink.co.jp, linux-kernel@vger.kernel.org Return-path: Received: from fire.osdl.org ([65.172.181.4]:62850 "EHLO smtp.osdl.org") by vger.kernel.org with ESMTP id S261922AbVEKIUK (ORCPT ); Wed, 11 May 2005 04:20:10 -0400 To: fs In-Reply-To: <1115837231.3599.55.camel@CoolQ> Sender: linux-fsdevel-owner@vger.kernel.org List-Id: linux-fsdevel.vger.kernel.org fs wrote: > > --- linux-2.6.11.8-orig/fs/buffer.c 2005-05-11 14:41:03.000000000 > -0400 Your email client wordwrapped the patch. Please fix it. > +++ linux-2.6.11.8/fs/buffer.c 2005-05-11 14:38:55.000000000 -0400 > @@ -2105,7 +2105,6 @@ int block_read_full_page(struct page *pa > memset(kaddr + i * blocksize, 0, > blocksize); > flush_dcache_page(page); > kunmap_atomic(kaddr, KM_USER0); > - set_buffer_uptodate(bh); > continue; > } > /* This patch will break the kernel's regular handling of file holes - !buffer_mapped() means that there was no disk mapping for this buffer: it sits over a hole in the file. Zeroing out the buffer and marking it uptodate is correct behaviour. You probably want something like this: --- 25/fs/buffer.c~a 2005-05-11 01:15:13.000000000 -0700 +++ 25-akpm/fs/buffer.c 2005-05-11 01:16:39.000000000 -0700 @@ -2094,9 +2094,12 @@ int block_read_full_page(struct page *pa continue; if (!buffer_mapped(bh)) { + int err = 0; + fully_mapped = 0; if (iblock < lblock) { - if (get_block(inode, iblock, bh, 0)) + err = get_block(inode, iblock, bh, 0); + if (err) SetPageError(page); } if (!buffer_mapped(bh)) { @@ -2104,7 +2107,8 @@ int block_read_full_page(struct page *pa memset(kaddr + i * blocksize, 0, blocksize); flush_dcache_page(page); kunmap_atomic(kaddr, KM_USER0); - set_buffer_uptodate(bh); + if (!err) + set_buffer_uptodate(bh); continue; } /* _